You have to create a class inside the style tags like in the example (see below for example shown in challenge):

<style>
.larger-image {
width: 500px;
}
</style>

In the example above, the class name is larger-image and has the property width set to 500px. The dot in front of larger-image indicates this is a class.

You have already added the correct class name “smaller-image” to img tag as specified by the instructions, now you just need to define what properties smaller-image class should have per the instructions.